The present invention relates to an electric power supply device for a mobile vehicular apparatus with an aerial cabin which has a force-feedback manipulator of a master/slave type which is actuated by a DC power supply.
There are known mobile vehicular apparatus with aerial cabins or platforms which have force-feedback manipulators of the master/slave type that are actuated by DC power supplies. The force-feedback manipulator has a master control arm including electric actuators associated with respective axes. Heretofore, these electric actuators are powered by a power supply device 50 as shown in FIG. 3 of the accompanying drawings. The power supply device 50 comprises an AC generator 51 connected through an AC/DC inverter 52 to electric actuators or motors 55a through 55d. AC electric energy generated by the AC generator 51 is converted by the AC/DC inverter 52 into DC electric energy which is then supplied to the electric actuators 55a through 55d.
Since, however, the AC generator 51 is connected through the AC/DC inverter 52 to the electric actuators 55a through 55d, the output voltage of the AC generator 51 varies as the rotational speed of the AC generator 51 varies. Therefore, the acceptable range of input voltages applied to the AC/DC inverter 52 has to be wide, and hence it causes a problem that the AC/DC inverter 52 must be large in size. Another problem is that when the AC generator 51 stops its operation, no electric energy is supplied to the electric actuators 55a through 55d. Also, when a large load is applied to a slave manipulator arm of the manipulator, the electric actuators 55a through 55d, which serve as force-feedback units for the master control arm, require a large amount of electric energy. Therefore, it causes a further problem that the electric generating capability of the AC generator 51 must be large enough to generate a required amount of electric energy, with the result that the AC generator 51 has to be large in size.